Adjustable leg means and automatic leg lift mechanism therefor



J. WISEMAN Dec. 18, 1962 ADJUSTABLE LEG MEANS AND AUTOMATIC LEG LIFT MECHANISM THEREFOR Filed Sept. 5, 1961 INVENTOR. JOSE H WISE N BY 41'! WW HI T0RNEY United States Patent 3,069,212 ADJUSTABLE LEG MEANS AND AUTOMATIC LEG LIFT MECHANISM THEREFOR Joseph Wiseman, 237 S. 4th E., Salt Lake City, Utah Filed Sept. 5, 1961, Ser. No. 135,958 1 Claim. (Cl. 311-39 The present invention relates to automatically extensible leg structures and actuating mechanisms therefor for utility objects such as chairs, tables, and the like and, more particularly, to new and improved, adjustable leg means and automatic leg lift mechanisms therefor, for incorporation with utility item's wherein the raising or lowering thereof may be accomplished in a very easy and etficient manner.

An object of the present invention is to provide extensible leg means for chairs, tables and the like which possess the feature of being automatically extensible, under self-contained spring pressure, when the detent means associated therewith is manually released.

A further object of the invention is to provide extensible leg means, wherein, when the detent means as sociated therewith is released, the leg means will extend downwardly so as to lift the object it is supporting, the spring pressure of the leg means being such that only'a very slight downward pressure is necessary to compress the legs as desired.

A further object of the invention is to provide new and improved leg support means wherein pairs of the same may be coupled together to a suitable tie-rod structure such that the legs may be released from their past-chosen detent position simultaneously, the release of the legs thereby serving to lift the utility member which they' support to a new desired level.

A further object of the invention is to provide latch means wherein spring-loaded legs are secured inwardly preparatory to the collapsing or folding of the legs against the utilitymember which is to'be supported by the same, this preparatory to transport.

A further object is to provide a combination latch and detent means which is spring loaded and tie-rod actuated by a common lever to effect optimum results of the operating mechanism.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claim. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view in reduced scale of one type of utility member which is supported ,by the leg structure of the present invention.

FIGURE 2 is a bottom plan, shown in fragmentary view and cut away for convenience of illustration, of a representative half of the structure of FIGURE 1.

FIGURE 3 is an enlarged, fragmentary view, partially in section, and taken along the line 3--3 in FIGURE 2.

FIGURE 4 is a section taken along the line 4-4 in FIGURE 3.

In the drawings the numeral indicates generally .a utility member, such as a table top, which may be ber 12 is pinned at 13' (see FIGURE 3) to a double yoke-type brace member 14, the latter being provided with flanges 15 which are secured by wood screws or other suitable means 16 to the utility member 10.

The pin means 13' enables the collapse of the several leg means 11 against the under-surface of utility member 10. When extended for support as shown in the drawings, the representative leg means 11 is maintained in its normal position relative to utility member 10 by brace means 17, the latter being slotted at 19 and provided with wing nut attachment 20. Obviously, other types of releasable securing means may be employed to secure the leg means 11 in rigid position. Additional rigidity may be given the structure by the provision of additional support to member 14 by brace 21, the same being secured by means 22 to utility member 10 by conventional pivot attachments 2.2, whereas brace 21 may be bolted at 23 to the double yoke member 14. The construction above described has been found to be unusually rigid and most satisfactory.

Inner tubular member 13 is provided with elongate, longitudinal side slots 26 (at least one but preferably two diametrically opposed slots) as shown in FIGURE 3. These slots 26 accommodate the positioning therethrough of pin 27, the same being secured in place by cotter 28. As shown in FIGURE 4, apertures 29 in member 12 provide access and mounting for pin 27.

The end 30 of tension spring 31 is mounted to pin 27 as shown in FIGURE 4. The remaining end 32 is secured to a pin-type retaining means 33, the latter being fixedly secured transversely to the inner tubular member 13 as shown in FIGURE 3.

It will be noted that the action of tension spring 31 is to draw the inner tubular member 13 outwardly from the outer tubular member 12. This is desired since, when the detent means is released (hereinafter to be described), the legs in the unit of FIGURE 1 will automatically extend themselves as the user releases the detent means. Thus, the only pressure the user will ever have to exert in adjusting the device will be a slight downward pressure upon utility member 10 when this member is desired to be in a lower position.

A caster 34, wheel means, or other suitable means may be secured to the lower end of inner tubular member 13 as desired.

As to the detent means employed, the same is indicated generally by the arrow number 35 and includes a latching dog 36 with its lever 37 pivoted to outer tubular member 12 by pin or other means 38. The lever 37 may be secured to pin 38 by conventional set screw 39. One arm 49 of lever 37 has provided a spring 41 which may be appropriately secured as at 42 to outer tubular member 12. The remaining arm 43 of lever 37 may include a U-configured member 44 which is secured to lever 37 by suitable attachments 45. Member 44 envelops a substantial portion (but generally less than of outer tubular member 12. Member 44 simply serves as a convenient stop when the detent release for the legs is actuated. Arm 40 of lever 37 is directly connected by chain 46 and inter-coupling tie rod 47 to lever 48. The cooperating tie rods 47 and 47 of each leg set form a mechanical couple about the axes A of lever pivot pin 49. Lever 48 is preferably L-shaped as shown so that a simple upward pressure in the form of a gripping action (e.g. thumb on table top 10 and fingers gripping upwardly on lever 48, on each side of table) is all that is necessary to release latch dog 36 in FIGURE 3. The construction will be the same on both sides of the table with the levers 48 being disposed diametrically opposite.

To complete the structure for the detent 3 5, the inner tubular member 13 is supplied with a plurality of mutually spaced, elongately oriented, recess configured latching teeth 50. Only two are shown in FIGURE 3. However, it will be understood that more may be supplied if desired. a

The operation of the latching teeth is as follows. When the user depresses the lever 48 as indicated by the arrow, the latch dog is released, i.e. withdrawn, so that the pressure of spring 31 will urge outwardly the inner tubular member 13 from without tubular member 12. The table will rise accordingly, and this rise may be regulated by the appropriate hand pressure of the user upon the top of the member by means of his thumbs. When the proper height has been reached, the pressure will be released from lever 48. Thus, the very next tooth depression as at 51 will receive the latching dog 36. Further rise is made impossible by virtue of the sloping character of the teeth and latching dog surfaces. Loads upon the utility surface 10 will not alter the leg disposition owing to the ratchet direction of the latching of the leg.

It should be noted in passing that the latching dog 36 is supplied with an access aperture 53 through outer tubular member 12 for accomplishing the above objects. An optional feature is to supply a latching aperture 54 which may be retentively engaged by the latching dog 36. This is particularly true when the latching dog 36 is supplied with a recess 55 which engages the wall of inner tubular member 13. Thus, the inner tubular member 13 may be completely depressed and the latching dog 36 engage the inner tubular member at latching aperture 54 so that there will be no possible inadvertent release of the legs when the legs are collapsed or folded against the utility member 10 for transit.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art-that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claim is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

Adjustable leg means including, in combination, a

utility member to be elevated and lowered, a plurality of leg means secured to said utility member, each of said leg means comprising: an outer tubular member; means securing said outer tubular member to said utility member; an inner tubular member telescopically disposed within said outer tubular member and adapted for floor contact, said inner tubular member being provided with elongate, side slot means; pin means disposed transversely within said inner tubular member, passing through said slot means thereof, and afiixed to said outer tubular member; tension spring means secured at one end thereof to said pin means; retaining means afiixed to said inner tubular member for fixedly receiving and securing the remaining end of said spring means variably remotely from said pin means; and normally engaged, manually releasable detent means for selectively fixing the relative dispositions of said inner tubular member and said outer tubular member, said spring means, when said detent means is released, operating to urge outwardly and thereby extend said inner tubular member from said outer tubular member, and wherein said adjustable leg means also includes a pair of upwardly displaceable lever means journalled to said utility member, on opposite sides thereof, tie rod means respectively coupled in mechanical couples between their respective detent means and their points of coupling to said lever means on opposite sides of their respective pivot axes, and independent tension spring means coupled between said detent means and said leg means for urging said detent means into engagement when so aligned for engagement in the absence of lever displacement.

References Cited in the file of this patent UNITED STATES PATENTS 744,613 Reirnold Nov. 17, 1903 1,827,985 Hunkele Oct. 20, 1931 1,888,478 Steidl Nov. 22, 1932 2,614,012 Yuan Oct. 14, 1952 2,659,414 -Hoar Nov. 17, 1953 2,672,385 Segal Mar. 16, 1954 2,698,442 Travis Jan. 4, 1955 2,977,168 Johnson Mar. 28, 196 1 

